Answer:
Mass number = 195
Step-by-step explanation:
Isotope:
An atom of an element that contain same atomic number but different atomic mass.
The difference in atomic mass is due to the different number of neutrons present, but the number protons and electrons are remain same.
In given isotope of an atom there are 85 protons and 85 electrons while number of neutrons are 110.
The number of electron or number of protons are called atomic number while mass number of an atom is sum of protons and neutrons. The umber of protons and electrons are always equal to make the atom electrically neutral and when an atom loses its valance electron the number of protons increases and thus positive charge increased and atom form cation.
Mass number = number of protons + number of neutrons
Mass number = 85 + 110 = 195